An air disk brake system using compressed air is employed in a large-sized commercial motor vehicle such as a track and a bus. Here, a brief description will be made of a constitution of a general air disk brake system. FIG. 40 is a schematic sectional view showing the constitution of the general air disk brake system. Referring to FIG. 40, an air disk brake system 101 includes a brake cylinder (not shown) having an actuator rod 102, a lever 103 connected to one end of the actuator rod 102, a rotation member 104 connected to the other end of the lever 103, a rocking bearing 105 rotatably supporting the rotation member 104, a connection part 107 provided at an eccentric position with respect to the rotation member 104, a traverse 106 having one end connected to the connection part 107, right and left brake pads (not shown) working with the traverse 106, and a rotor (not shown) arranged between the right and left brake pads. According to the air disk brake system 101, the rotor is sandwiched by the right and left brake pads by use of the compressed air supplied from the brake cylinder through the lever 103 and the like.
In addition, such air disk brake system is disclosed in Japanese National Publication PCT application No. 8-504250 and WO2006/002905A1.
A brief description will be made of a constitution of the rocking bearing in the above air disk brake system. The rocking bearing has an outer ring for the rocking bearing, a plurality of rollers, and a retainer to retain the rollers. The outer ring for the rocking bearing is not in the form of a ring, and it is provided by splitting a cylindrical member at two circumferential points. The retainer also has a configuration provided by splitting a cylindrical member at two circumferential points and following the outline of the outer ring for the rocking bearing. When the rocking bearing having the above constitution is assembled, the rollers are incorporated in pockets of the retainer first, and the retainer having the rollers is arranged on the inner diameter side of the outer ring for the rocking bearing.
Here, after the rocking bearing has been assembled, the movement of the retainer toward the inner diameter side is not restricted. Thus, when the assembled rocking bearing is mounted on the air disk brake system having the above constitution, the retainer could be moved toward the inner diameter side and drop out of the outer ring for the rocking bearing.